disease Flashcards
effect of HIV
aids it affected by hiv
Spread by direct contact with infected body fluids e.g. blood,
semen, breast milk.
Destroys white blood cells making the individual immunodeficient and increasingly susceptible to other diseases. Leads to AIDS.
Use of condoms and protected sex.
Needle exchange.
Screening blood for HIV.
Deterring infected mothers from
breastfeeding.
effect of chlamydia
if left untreated Causes infertility in adults, conjunctivitis and
lung problems in babies.
Antibiotics like tetracycline
Sexually transmitted, use condoms to prevent spread.
tablets
as tetracycline or erythromycin.
effect of malaria
Destroys red blood cells causing fever.
Prevent the mosquitos biting and infecting people by:
* killing mosquitoes with insecticide
* releasing large numbers of infertile male mosquitoes
* biological control of mosquitoes
* use of mosquito nets and repellents.
penicillin
antibiotic
Pathogens are communicable, they can be spread by:
- contact
- aerosol
- body fluids
- water
- insects
- contaminated food.
types of microorganisms
● Bacteria
● Fungi (not all fungi are micro-organisms)
● Viruses
● Protists
pathogen
microorganism that causes disease
bacteria
single celled organism
structure of a virus
Their structure consists
of a central core of genetic material surrounded by a
protein coat. They do not contain a cytoplasm, nor a cell
membrane.
scientific names
chlamydia trachomatis (bacteria)
human immunodeficiency virus (virus)
plasmodium (protist)
acquired immunodeficiency syndrome
first line of defence
non specific prevents pathogen from entering the body
skin natural skin flora
blood clotting This seals wounds and stops the entry of microbes when the skin surface is cut.
2nd line of defence
immune system
types of white blood cells
phagocytes
engulf pathogens
lymphocytes which secrete antibodies and antitoxins (neutralise toxins
produced by the pathogen).
antigens
Antigens are molecules on the surface of all cells that are recognised by the immune system.
Pathogens have unique antigens on their surface. WBCs have specialised receptors which can
detect these foreign antigens on pathogens, triggering an immune response.
antibodies
Antibodies are proteins produced by lymphocytes in response to a foreign antigen. Each antibody
is specific to an antigen and binds to it. Antibodies cause the pathogen to clump together, disabling
them and facilitating ingestion by phagocy
memory cells
Memory cells are lymphocytes that remain in the body after a pathogen has been destroyed.
They provide immunity: if the body is re-infected, antibodies are produced more rapidly and the pathogen is destroyed before it can produce disease symptoms
vaccination
- Dead, weakened or inactivated pathogens are given to the patient.
- The antigens initiate an immune response resulting in the production of antibodies
- Memory cells are produced which remain in the body, providing long-term immunity
disadvantages of vaccines
Concerns about potential side effects/adverse reactions.
● Religious or cultural objections.
● Not guaranteed to work.
● May cause upset to children.
● May believe that vaccines are linked to other diseases such as autism, asthma etc.
what is an antibiotic
Antibiotics are substances produced by living organisms (e.g. fungi) that kill or inhibit the growth of
bacteria (no effect on viruses).
why are bacteria becoming resistant
Due to overprescription and antibiotic misuse (e.g. not completing the entire course), bacteria are
becoming increasingly resistant to antibiotics.
what is a highly resistant strain of bacteria
MRSA resistant to nearly all antibiotics
Control measures to prevent infection by MRSA:
● New patients screened for MRSA.
● Stringent hygiene measures in hospitals (hospital staff, patients and visitors).
Control measures to prevent the development of new resistant strains:
Prescribe antibiotics only when necessary.
● Ensure patients complete their antibiotic courses.
● Variation in the types of antibiotics prescribed.
what is a drug
A drug is a substance that affects chemical processes within the body they must undergo testing
monoclonal
Monoclonal antibodies are identical antibody clones cultured from one parent lymphocyte
cell.
monoclonal antibodies production
- Specific antigen injected into an animal e.g. mouse.
- Lymphocytes producing complementary antibodies extracted.
- Lymphocytes are fused with tumour cells to form hybridoma cells.These hybridoma cells are now capable of replicating rapidly and producing antibodies.
- Hybridoma cells cultured.
- Monoclonal antibodies collected and purified
monoclonal antibodies for cancer
Monoclonal antibodies specific to cancer cells are attached to an anti-cancer drug. This
allows chemotherapy drugs to target cancerous cells only.
tissue typing
for transplants
Monoclonal antibodies can be used to match donor organs to patients before
transplantation. This reduces the chance of a transplanted organ being rejected.
cholora just in case
cholera is caused by the bacterium Vibrio cholerae and
structure of a bacteria
cell wall cell membrane cytoplasm
and a loop of genetic material
how is malaria spread
Malaria is caused by the single-celled organism Plasmodium. Plasmodium is spread via female mosquitoes of the genus Anopheles
Anopheles mosquitoes bite humans and inject Plasmodium into the blood stream.
bodys primary response
is slow produces memory cells specific tot he antigens encountered
secondary immune response
The response of lymphocytes to the antigen is faster, more antibodies are produced and the response lasts for longer. This is due to memory cells that can multiply rapidly and produce antibodies very quickly following the second invasion.
does the person experience any symptoms
This means that there are usually no noticeable signs of the disease (the antibodies destroy the invading microbe before symptoms appear). The person has, in other words, become immune to the disease.
why do people suffer from the flu many times in thier life
this is because the antigens on the surface of the flu virus mutate and change rapidly, giving rise to new strains which have not been previously encountered and so immunity has not developed.
drug trials
The drug is tested on human cells grown outside the body in a laboratory.
The drug is then tested on animals.
The drug is tested on healthy volunteers.
Further trials are carried out to establish the optimum dose for the drug.
The drug is then trialled with a sample of people who have the disease or condition it is intended to treat. This is to see if it is more effective than current treatments.
If all these tests are passed, the drug is then licensed for general use.
drug trials
The drug is tested on human cells grown outside the body in a laboratory.
The drug is then tested on animals.
The drug is tested on healthy volunteers.
Further trials are carried out to establish the optimum dose for the drug.
The drug is then trialled with a sample of people who have the disease or condition it is intended to treat. This is to see if it is more effective than current treatments.
If all these tests are passed, the drug is then licensed for general use.
what is a double blind trial
when the researcher and the volunteers dont know if they are taking the drug or the placebo
what are other medical uses of monoclonal antibodies
Monitoring the spread of malaria
Destruction of cancer cells
how does a bacteria become antibiotic resistant
The development of antibiotic resistance happens because of a mutation in the bacteria,
monoclonal antibodies
a disses ids inserted into a lab mouse.
the mouse will produce lymphocytes that will make antibodieswhich will target the specific antigen.
In this process, B-lymphocytes are fused with myeloma cells (tumour cells )(cancer cells are used because they keep growing and dividing indefinitely) forming a hybridoma.
This divides rapidly in laboratory conditions to form a clone.
The hybridoma continuously produces specific antibodies called monoclonal antibodies.
story of malaria
Malaria is caused by the single-celled organism Plasmodium. Plasmodium is spread via female mosquitoes of the genus Anopheles
. Anopheles mosquitoes bite humans and inject Plasmodium into the blood stream. Plasmodium causes a fever when it destroys red blood cells in humans.
Treatment consists of killing Plasmodium with anti-malarial drugs, such as paludrine or daraprim.
A vaccine against Plasmodium has been developed. Prevention methods include killing mosquitoes with insecticide, releasing large numbers of infertile male mosquitoes, biological control of mosquitoes, and use of mosquito nets and repellents.
